Isolation of antibacterial compounds from chloroform extract of neem (Azadirachta indica A. Juss.) leaves guided by bioautography

Abstract

Abstract. Neem leaves (Azadirachta indica A. Juss.) have been traditionally used as an antibacterial agent for a long time. Former research mentioned that neem leaves were proven to have antibacterial activity. This study was aimed to isolate antibacterial components in the chloroform extract of neem leaves guided by bioautography. The maceration technique extracted neem leaves. Antibacterial testing of chloroform extract was conducted by the agar dilution method. Chloroform extract at 1000 µg/mL concentration inhibited the growth of Staphylococcus aureus but not Escherichia coli. The extract was then fractionated by Vacuum Liquid Chromatography (VLC) method, and the fractions obtained were tested for antibacterial activity. The mixture of 2 and 3 fractions eluted with n-hexane: ethyl acetate = 9:1 (v/v) and n-hexane: ethyl acetate = 5:1 (v/v), inhibited the growth of S. aureus at the concentration of 1000 µg/mL. TLC-bioautography of the fraction showed two inhibition zone with hRf values of 43.75 and 18.75. Isolate with hRf of 18.75 has a Minimum Inhibitory Concentration (MIC) value of 500 µg/mL and still contains many components such as terpenoid.